This invention relates in general to a flat plasma display panel and in particular to an improved structure for a full color, high resolution capable flat plasma display panel which operates at a high efficiency and includes independent trigger and controlled sustaining electrodes.
A flat plasma display panel is an electronic display in which a large orthogonal array of display pixels, such as electro-luminescent devices, AC plasma display panels, DC plasma display panels and field emission displays and the like form a flat screen.
The basic structure of an AC Plasma Display Panel, or PDP, comprises two glass plates with a conductor pattern of electrodes on the inner surfaces of each plate. The plates are separated by a gas filled gap. The electrodes are configured in an x-y matrix with the electrodes on each plate deposited at right angles to each other using conventional thin or thick film techniques. At least one set of sustaining electrodes of the AC PDP is covered with a thin glass dielectric layer. The glass plates are assembled into a sandwich with the gap between the plates fixed by spacers. The edges of the plates are sealed and the cavity between the plates is evacuated and filled with a mixture of neon and xenon gases or a similar gas mixture of a type well known in the art.
During operation of an AC PDP, a sufficient driver voltage pulse is applied to the electrodes to ionize the gas contained between the plates. When the gas ionizes, the dielectrics charge like small capacitors, which reduces the voltage across the gas and extinguishes the discharge. The capacitive voltages are due to stored charge and are conventionally called wall charge. The voltage is then reversed, and the sum of the driver voltage and wall charge voltages is again large enough to excite the gas and produce a glow discharge pulse. A sequence of such driver voltages repetitively applied is called the sustaining voltage, or sustainer. With the sustainer waveform, pixels which have had charge stored will discharge and emit light pulses at every sustainer cycle. Pixels which have no charge stored will not emit light. As appropriate waveforms are applied across the x-y matrix of electrodes, small light emitting pixels form a visual picture.
Typically, layers of red, green or blue phosphor are alternately deposited upon the inner surface of one of the plates. The ionized gas causes the phosphor to emit a colored light from each pixel. Barrier ribs are typically disposed between the plates to prevent cross-color and cross-pixel interference between the electrodes. The barrier ribs also increase the resolution to provide a sharply defined picture. The barrier ribs further provide a uniform discharge space between the glass plates by utilizing the barrier rib height, width and pattern gap to achieve a desired pixel pitch.
Further details of the structure and operation of an AC PDP are disclosed in U.S. Pat. No. 5,723,945 titled xe2x80x9cFLAT PANEL DISPLAYxe2x80x9d; U.S. Pat. No. 5,962,983, entitled xe2x80x9cMETHOD OF OPERATION OF DISPLAY PANEL xe2x80x9d; and U.S. patent application Ser. No. 09/259,940, filed Mar. 1, 1999, entitled xe2x80x9cFLAT-PANEL DISPLAYxe2x80x9d, all of which are incorporated herein by reference.
This invention relates to an improved plasma flat plasma display panel which operates at a high efficiency and includes independent trigger and controlled sustaining electrodes.
It is known to manufacture plasma flat plasma display panels having pairs of sustaining electrodes which establish a charged volume between the display substrates. The charge supports a plasma discharge that is controlled by applying voltages to a plurality of address electrodes. The charged volume is established by applying an initial voltage to the sustaining electrodes. The actual plasma discharge is initiated between the sustaining electrodes by applying a second sustaining voltage to the sustaining electrodes. The efficiency of the panel is generally greater when gas and geometry parameters are adjusted to increase the voltage required to sustain a discharge. However, this causes complexity for the associated voltage supply circuits with respect to the initiating voltage. Therefore, it would be desirable to develop a plasma display panel that would allow initiation and control of the sustaining discharge with a relatively low voltage while sustaining the resulting plasma discharge with a relatively high voltage.
It is also known to provide each of the electrodes in a plasma display panel with a separate voltage driver. The total number of voltage drivers and their physical connections to the panel electrodes add considerable bulk and cost to the final display panel. Accordingly, it also would be desirable to reduce the number of separate voltage drivers.
The present invention contemplates a plasma flat-panel display having a first transparent substrate with a first pair of parallel sustainer electrodes deposited upon thereon. The first pair of sustainer electrodes include a first sustainer electrode and a second sustainer electrode. The display also includes at least one auxiliary electrode deposited upon the first substrate parallel to the first pair of sustainer electrodes and adjacent to the first sustainer electrode in the first pair of sustainer electrodes. A second pair of parallel sustainer electrodes is deposited upon the first substrate parallel to the auxiliary electrode, the second pair of sustainer electrodes including a first sustainer electrode and a second sustainer electrode. The second sustainer electrode pair is oriented upon the first substrate as a mirror image of the first sustainer electrode pair with the first sustainer electrode in the second pair of sustainer electrodes adjacent to the auxiliary electrode. A single common first sustainer electrode pad is electrically connected to the first sustainer electrode in the first sustainer electrode pair and the first sustainer electrode in the second sustainer electrode pair. The first sustainer electrode pad is adapted be to connected to a first sustainer voltage waveform supply so that a single supply provides a first sustainer voltage waveform to both of the first sustainer electrodes. A layer of dielectric material covers the sustainer and auxiliary electrodes. A protection layer is formed covering the dielectric layer. The display further includes a second substrate which is hermetically sealed to the first substrate with the second substrate having a plurality of micro-voids formed in a surface thereof that is adjacent to the first substrate. The micro-voids are filled with a gas and cooperate with the first substrate to define a plurality of sub-pixels. A phosphor material is deposited within each micro-void and a plurality of address electrodes are incorporated within said second substrate. Each of the address electrodes correspond to one of the sub-pixels.
The present invention also contemplates a method for operating a plasma flat-panel display that includes applying in a set-up period first and second sustain, auxiliary, and address voltage waveforms to corresponding electrodes. Similar electrodes are connected by pads to cause the setting of all wall charge on associated dielectric surfaces corresponding to the controlled discharge volumes of sub-cells to values appropriate to an xe2x80x9coffxe2x80x9d state. A first auxiliary voltage waveform is then applied in an addressing period in conjunction with an address voltage waveform sequentially for each auxiliary voltage waveform supply connected by pads to corresponding first auxiliary electrodes. The first auxiliary voltage waveform selectively initiates discharges between associated first and second sustain electrode pairs, thereby setting the wall charge on the dielectric surfaces associated with the sustainer electrodes corresponding to the controlled discharge volumes of selected sub-cells to values appropriate to an xe2x80x9conxe2x80x9d state. Subsequently, a pre-determined number of voltage pulses via first and second sustain waveform supplies are applied during a sustaining period to create a pre-determined number of discharges in a sequence corresponding to the voltage pulses in cells set to an xe2x80x9conxe2x80x9d state with the discharges controlled in position and shape by auxiliary voltage waveform supplies.
Various objects and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings.